WHALE Watermaster Carver Crystal Submersible Water Pump Assembly , 12V High Flow suitable for Carver and Truma Crystal Water Inlets. Simplifies the connection between an outside water container and the caravan. Simply drop the 12v Submersible Pump into a Water Container and plug into the side of the Caravan or Motorhome. Suitable for both microswitched or pressurised systems. Incorporates an anti air-locking pump enhancing the performance of the WHALE water system.